Method for filling electrically charged receptacle



Feb. 25, 1964 J. G. BECK ETAL METHOD FOR FILLING ELECTRICALLY CHARGEDRECEPTACLE 2 Sheets-Sheet 1 Filed March 20, 1958 J. G. BECK G. E. F.BREWER G. L. BURNSIDE J. W. MISTELE J. SMARSH FIG. 4

INVENTORS 6121b BY 6. FMMMM &

ATTORNEYS Feb. 25, 1964 J. G. BECK ETAL 3,122,320

METHOD FOR FILLING ELECTRICALLY CHARGED RECEPTACLE Filed March 20, 19582 Sheets-Sheet 2 FIG. 2B

J.G. BECK G.E.F. BREWER e.| BURNSIDE J.W. MISTELE J. SMARSH INVENTORS 5.9. 22261) Ema ATTORNEYS United States Patent 3,122,320 METHGD FGR FELINGELECTRICALLY CHARGED RECEPTACLE Jerry G. Beck, Oak Park, George E. F.Brewer, Walled Lake, Gilbert L. Burnside, Oak Park, John W. Mistele,Detroit, and Joseph 'Smarsh, Livonia, Mich, assignors to Ford MotorCompany, Dear-born, Mich, a corporation of Delaware Filed Mar. 20, 1958,Ser. No. 722,712 2 Claims. (Cl. 239-3) This invention relates to thehandling of electrostatic spraying materials and more particularly to amethod for replenishing water base paint consumed from an electricallycharged paint pot.

In the usual installation for the electrostatic spraying of solvent typepaints, the receptacle or paint pot which holds the paint reserve isgrounded and a high potential is applied to, or adjacent to, a sprayinghead or atomizing nozzle. The spraying device is usually connected toreceive paint from the receptacle by a dielectrical tube, such asrubber, and the column of paint therein being relatively non-conductiveserves to isolate the electrically charged spray head from the groundedreceptacle. However, the use of conductive water base paints requiresthat the paint pot be insulated from ground since the column of paintcarries the hi h potential from the spray head to the paint pot.

Prior to this invention, in order to replenish the paint pot, it wasnecessary to shut down the apparatus and bleed or? any remaining chargein the paint receptacle prior to filling. The method which we herebyprovide permits either the intermediate or continuous filling of thereceptacle while it remains charged. Essentially, we move isolated unitquantities or particles of the water base paint from a grounded supplysource through the air and deposit them into the charged container.

It is, therefore, an object of this invention to provide a method ofreplenishing an electrically charged water base paint receptacle.

This and other objects of our invention will become apparent from thefollowing description in which:

1G. 1 illustrates a form of our invention as applied to an electrostaticspraying arrangement; and

FEGS. 2a, 2b, 3a, 3b, and 4 disclose alternate arrangements for thepractice of our invention.

Referring to H6. 1, a paint pot is shown generally at 19 and contains awater base paint 21 which will be electrostatically applied. Flexiblepipe 13 is connected to receive paint from pot 1t and convey it to arotating cup atomizing head 14. A high potential from power supply 15 isapplied to head 14 and causes the paint particles atomized by thespinning cup to be electrostatically charged and carried to an articleupon which they will be deposited in a manner which is well known andunderstood in the art.

Receptacle 1'? is insulated from ground by dielectrical 11 which, inturn, is supported on grounded plate 12. For the purpose of filling thereceptacle, in accordance with this invention, we provide a receivingfunnel 26 with a neck extending through the top and into receptacle 1% Asupply of water base paint is shown generally at 16 and a conduit 17leads therefrom to a head 18 which may take the form of a sprinkler orshower head having perforations 22 formed therein. An intermediatereceiving funnel 19, if desired, may be positioned between the head 18and receiving funnel 20. Head 18 is grounded as shown. In the operationof this embodiment, replenishing paint from source 16 is sprayed orotherwise broken into discrete particles by perforated head 18. Theseparticles fall freely through the air space between head 18 and funnel19 and then pass through a second air space into receiving funnel 20.The purpose of intermediate funnel 19 is to collect any scattereddroplets from head 18 that would not otherwise enter funnel 243. Thefirst air space defined between head 18 and intermediate funnel 19 andthe second air space between funnel 19 and receiving funnel 2i serve toisolate the grounded head 18 from the charged paint pot 1t). Funnel 19may assume a potential intermediate that of the head 18 and thereceiving funnel 2%.

FIG. 2 shows an arrangement for the transfer of larger quantities ofwater base paint from the source 16 into the paint pct 10 by means of anintermediate movable transfer vessel 36. Vessel 3b is insulated fromground and in the raised position shown by FIGURE 2(a) it may be filledthrough pipe 17 from source 16, then lowered and the contents dischargedinto pot 15) as shown in FIG. 2(b). We preferably provide two feet ofair space between the bottom of the movable transfer vessel 3% and thetop of pot 19 with the vessel in the raised position and two feet ofspace between pipe 17 and the top of the transfer vessel 3%; with thevessel in the lowered position.

FZGS. 3(a) and 3(2)) show another arrangement for replenishing the potin accordance with the teaching of this invention wherein anintermediate isolated transfer vessel 31 is iixed in space between pipe17 and pot 10 and is provided with a retractable fill ng pipe 32 bywhich the vessel may be filled from grounded source 16 through pipe 17.Filling pipe 32 is then lowered into vessel 31 upon the completion ofthe filling. Pot 1b is also provided with a retractable filling tube 33which is lowered into the pot when not in use but which may be extendedto receive paint from the transfer vessel. We preferably provide twofeet of air space between the top of the intermediate vessel 31 and thefilling pipe 17 and between the bottom of the vessel and the paint pot16.

IN FIG. 4 we illustrate a further embodiment of our method. We provide afunnel 35 with a neck in communication with pot 1t and a substantiallyhorizontal receiving throat. A pump 3'7 delivers paint under pressurefrom supply 16 to a nozzle 36 where the paint is broken into discreteparticles and directed into the throat of the funnel. The inertia thusgiven the particles carries them through the air space and into thefunnel 36 where they collect and drain into pot 10 thereby replenishingthe paint supply.

It is, therefore, apparent that we have provided a method for thefilling of a charged paint pot either continuously or intermediatelyfrom a grounded supply of water base paint without the necessity ofremoving the charge from the paint pot or otherwise interfering with thespraying operation.

We claim:

1. A method for transferring an electrically conductive paint from asource at a substantial ground potential to a receptacle at asubstantial electrical potential with reference to the ground potentialof the source, comprising the steps of spraying the paint from saidsource into paint particles, receiving said paint particles in areceiving funnel, conducting the paint from said receiving funnel intothe receptacle, positioning an intermediate funnel between said sourceand said receiving funnel, maintaining said intermediate funnel at anelectrical potential intermediate the ground potential of said sourceand the electrical potential of said receptacle, collecting a portion ofsaid particles not received by said receiving funnel in saidintermediate funnel, and directing said portion collected in saidintermediate funnel to said receiving funnel to prevent the loss ofpaint in the transfer of the latter from said source to said receptacle.

2. A method for transferring an electrically conductive paint from asource at a substantial ground potential to a receptacle at asubstantial electrical potential with reference to the ground potentialof the source, said source being spaced from said receptacle, saidmethod comprising the steps of spraying the paint from said source intopaint particles, transferring said particles through air into areceiving funnel, said receiving funnel being carried by and assumingthe potential of said receptacle, conducting the paint from saidreceiving funnel into said receptacle, positioning an intermediatefunnel between said source and said receiving funnel, insulating saidintermediate funnel from said source and from said receiving funnel,maintaining said intermediate funnel at an electrical potentialintermediate the ground potential of said source and the electricalpotential of said receptacle, collecting a portion of said particles notreceived by said receiving funnel in said intermediate funnel, anddirecting said portion collected in said intermediate funnel into saidreceiving funnel to prevent the loss of paint in the transfer of thelatter from said source to said receptacle.

References Cited in the file of this patent UNITED STATES PATENTS1,346,811 Diebold July 20, 1920 2,027,308 Schacht Jan. 7, 1936 2,358,227Hiers Sept. 12, 1944 2,675,330 Schwartz et a1 Apr. 13, 1954 2,826,513Blanchard Mar. 11, 1958 FOREIGN PATENTS 948,978 France Feb. 7, 1949421,811 Great Britain Dec. 20, 1934 793,958 Great Britain Apr. 23, 1958

1. A METHOD FOR TRANSFERRING AN ELECTRICALLY CONDUCTIVE PAINT FROM ASOURCE AT A SUBSTANTIAL GROUND POTENTIAL TO A RECEPTACLE AT ASUBSTANTIAL ELECTRICAL POTENTIAL WITH REFERENCE TO THE GROUND POTENTIALOF THE SOURCE, COMPRISING THE STEPS OF SPRAYING THE PAINT FROM SAIDSOURCE INTO PAINT PARTICLES, RECEIVING SAID PAINT PARTICLES IN ARECEIVING FUNNEL, CONDUCTING THE PAINT FROM SAID RECEIVING FUNNEL INTOTHE RECEPTACLE, POSITIONING AN INTERMEDIATE FUNNEL BETWEEN SAID SOURCEAND SAID RECEIVING FUNNEL, MAINTAINING SAID INTERMEDIATE FUNNEL AT ANELECTRICAL POTENTIAL INTERMEDIATE THE GROUND POTENTIAL OF SAID SOURCEAND THE ELECTRICAL POTENTIAL OF SAID RECEPTACLE, COLLECTING A PORTION OFSAID PARTICLES NOT RECEIVED BY SAID RECEIVING FUNNEL IN SAIDINTERMEDIATE FUNNEL, AND DIRECTING SAID PORTION COLLECTED IN SAIDINTERMEDIATE FUNNEL TO SAID RECEIVING FUNNEL TO PREVENT THE LOSS OFPAINT IN THE TRANSFER OF THE LATTER FROM SAID SOURCE TO SAID RECEPTACLE.